I don't know about gun barrels, but if you Google "Terry Dean Weights" You'll find nose weights for it. He does have resin gear and bomb bay doors that are corrected from what is in the kit, if you fell you need to change it. The deicer boots were inflatable bladders. as the wing would ice, these could be turned on and they would cycle, breaking and ice accumulated on them. The rest of the sheet would then tear away from the wing. I don't know why they would be removed, other than weight. (I don't know what the icing conditions were at altitude in the Pacific, maybe they just weren't needed.)